One embodiment of an electrical component configured as a sensor is a magnetic field sensitive angle sensor, whose sensor element typically includes an integrated electronic circuit configured as an electronic chip which is soldered into a printed circuit board which typically includes additional electronic components e.g. configured as a processing circuit.
Typically a cable leads out of the housing through a pass through opening wherein the free insulation stripped ends of cable strands are sauntered with the processing onto the circuit board or a plug in jack is integrated in the pass through of the wall of the housing wherein externally accessible electrical contacts in an interior of the housing are connected with the processing circuit through individual strands of a conductive electrical cable.
Thus it is well known to configure the housing with a long term seal in that advantageously not only housing elements are bolted together with a seal arranged there between but the housing forms a welded or glued unit in that for example a cover is placed on a pot shaped housing and laser welded.
It is another protective measure to encase the electronic components including the chip in the interior of the housing with a hardening encasement compound before closing the housing, thus to cover the electronic components by covering the entire circuit board with the curing encasement compound.
Since conductive paths or at least soldering spots for soldering the outgoing cable or the outgoing strands of a cable at a bottom side of the circuit board which for this reason is mounted at a distance from the base of the pot shaped interior space at least a bottom side of the circuit board has to be encased at the provided electrical portions and components and also all additional exposed portions of electrical conductors thus the strand ends or when using a plug in jack the soldered joints between the exposed ends of the strands and the plug in jack.
Thus, it is typically required to encase a lower interior space below the circuit board and also an upper interior space above the circuit board with a hardening encasement compound before closing the housing.
In some applications an additional application of a cover is omitted since the lower interior space as well as the upper interior space is completely filled with the encasement compound so that the hardened encasement compound arranged above the printed circuit board represents the only protection for the electronic components relative to an outside.
It is appreciated that the enveloping housing has to have sufficient stability for an intended application in order to withstand loads that are applied from an outside, for example through the attachment of the housing at an adjacent component.
However it has become evident that the encased electronics can be damaged or destroyed even when the interior space of the sensor housing is completely encased, in particular when there are very high temperature variations.
Presumably these problems are caused by the temperature expansion of the hardened encasement compound which differs from a temperature expansion of the enveloping housing at least time based. In particular when the housing is closed tight by a cover that is additionally applied an expansion of the cured encasement compound which completely fills the interior space in parts considerable mechanical loads upon the electronic circuit so that for example even solder joints between an electronic component and the circuit board can tear off.